Complexing ability of glucaric acid (I), I/H3BO3 (1:1), I/H3BO3 (1:2), and Na tripolyphosphate for Ca ions was detd. at 4 pH values. There was no significant effect on increasing the proportion of H3BO3 to >50%. The complexing ability of I/H3BO3 system was low compared to that of Na tripolyphosphate. The complexing ability of H3BO3 was negligible.